Force constant decomposition for penta-coordinated XH3 Cl2- (X = C, Si, Ge) structures.

Based on the energy decomposition analysis of an interacting system, we propose a method for force constant decomposition analysis with respect to the specific normal coordinate. Using the presented method, we examined the penta-coordinated XH3Cl2- system (X = C, Si, Ge), which possesses a three-center four-electron bond. The origin of the difference in the stability of the penta-coordinated D3h structures was clearly shown to be the effect of electron delocalization-polarization term. © 2018 Wiley Periodicals, Inc.